Process and apparatus for removing drossy residues from vertical muffles in the extraction of zinc.



A. ROITZHEIM.

PROCESS AND APPARATUS FOR REMOVING DROSSY RESIDUES FROM VERTICAL MUFFLES IN THE EXTRACTION OF ZINC.

APPLICATION FILED sPT.22, 191a.

Patented June 22, 1915 4 SHEETS-SHEET}.

A. ROITZHEIM. PROCESS AND APPARATUS FOR REMOVING DROSSY RESIDUES FROM VERTICAL MUFFLES IN THE EXTRACTION 0F ZINC. APPLICATION FILED sEPT.22. I913.

1,144,066. Patented June 22, 1915.

4 $HEET$SHEET 2.

-i l: 9f2.

A. ROITZHEIM. PROCESS AND APPARATUS FOR REMOVING DROSSY RESIDUES FROM VERTICAL MUFFLES IN THE EXTRACTION 0F ZINC. APPLICATION FILED SEPT. 22. I913.

Patented June 22, 1915.

4 SHEETSSHEET 3.

A. ROITZHEIM. PROCESS AND APPARATUS FOR REMOVING DROSSY RESIDUES FROM VERTICAL MUFFLES IN THE EXTRACTION 0F ZINC.

APPLICATION FILED SEPT.22, 1913.

Patented June 22, 1915. I

4 SHEETS-SHEET 4.

Fig 7.

UNITED STATES PATENT OFFICE.

ALEXANDER ROITZHEIM, 0F DUISBURG, GERMANY.

PROCESS AND APPARATUS FOR REMOVING DROSS'Y RESIDUES FROM VERTICAL IVUTFILES IN THE EXTRACTION OF ZINC.

Application filed September 22, 1913.

To all whom. it may concern:

Be it known ,that I, ALnXANm a RorrzHmM, a subject. of the King of Prussia, German Emperor, and residing at the city of Duis burg, in the. Kingdom of Prussia, German lhnpire. ha we invented certain new and nseful Improvements in Processes and Apparatus for Removing Drossy Residues from Vertical Multlcs in the Extraction of Zinc, of which the following is a specification.

The smelting of Zinc ores in vertical niuflles for the purpose of zinc extraction presents no diiiiculties when the ores are not dressy, and has the advantage that the work of cleaning, out is very greatly facilitated. res ol this hind are however very rare and the majority of the ores employed in practice are more or less dross; The extent to which slugging occurs is manifested, according to the hind ot ore. in all stages hetueen only slight sintering and complete soft ning of -the residues of ore. The slugs do not'bccoine. actually liquid as this is" preu-nted by the excess of reducing carbon in the charge, just as the admixture of luuiotte with rich clay inalte it iint uhcn vertical mutilcs are employed for smelt ng such ores. just this sintered or soft slag. which is still far from the condition of a thin liquid. introduces the diiiiculty that the charge does not automatically slide doun tln'ough the mutlle. but n'1o --'tly remains adherent to the walls of the nnitlle. There il'ore uhen smelting dressy ores in vertical niutllr: the same cleaning work is neces ary as in lun'izontal mutllcs, whcrctorrthe cur ployment of vertical niullles has practically no advantages at aii as compared with that of horizontal inuillcs. In addition, hen the ores s very considerably, the devi es in the inutiles for dr -fi'ng oli the zinc vapors and reduction f. which dc- \ices. owing to the consitlcra li- I't iani'c otl'xrcd by the high column oi clan-e to the passage of vapors, are unvii-uhn' liv necessary in vertical inuliles. are soon rhoiccd up with incrustations of slag, and, tin: rontinual replacement. of these dcv ices involves unnec cssary expense.

The. present imention relates to obviating these. ditliculties.

It suoelantialhj onsists in a plston being prrssrd from above dovvn vaidiy through the inulile, the s nteicd or sco: ii-ed cont-cuts Specification of Letters Patent.

Patented June 22, 1915.

Serial No. 791.108.

of the. mullle being thus driven out. The

piston moves of course with a certain play paratively long mufllcs used for smelting zinc. and also in the event of working having to be continuous a single piston scarcely sutlices for each mutlie, but preferably several pistons are inserted into one mullle, as represented in the drawings.

Sonic. preferred forms of apparatus for carrying my process into practice are rcprcsented by way of example in the accompanying drawings, wherein:

Figure 1 is a longitudinal section through one inullle: Fig. 2 is a longitudinal section taken at right angles to the section plane of Fig. l. and Fig. I} is a cross section through the mulilc. F a. -1- 8 illustrate the type of inullie and pistons t'or ores that slag consection talc-n at right angles to Fig. 4; Fig. '3 a crossscction of the inullle taken through the fiune ducts on line A It Fig. 4; Fig. 7 a top plan view of the mulile, and Fig. 8 a cross ection of the inullle taken below the lame ducts on line 1 Fig. 1.

lii-t'i-rrinil' to the drawing, (7. is a. vertical nntlllc; it is located in a heating chamber ha\ingthe known construction of the gas or halt-has furnace.

('1 are gas dischar e ducts through which pa s the t'ediwtion a order that they may collect in the receivers 'ihesc ducts start at a certain distance below tln upper opening of the muliie and finish at a certain distance from the lower opening. so that the charge or the. residues reliably shut oil the outside air. In the, dra'iving. these ducts are shown as pcrfo ratr l \ulllSI instead of this device, another of the known devices of this kind can howe. er be employed. but. in any case, the withdrawal ot' the vapor is intended to begin at;

(l and to finish at e, in order that the vapors may be prevented from coming into contact with the outside air.

f are pistons which pass with the necessary play through the muffle.

The mode of working is as follows z--The mullie is filled, as shown, with the charge and the pistons. \Vhtn the charge is reduced by the action of the high temperature in the furnace chamber, the door of the bend or of a similar device is opened, and the charge therein consisting of reduced residues is withdrawn. Simultaneously mechanical pressure is applied from above to the top-piston and the latter is therefore pressed downwardly a certain distance. This distance corresponds to the length of the projection or separate stem h on the pis ton, and the arrangement is such that a fresh piston. which is set in place after the pressure member has been raised, stands somewhat above the upper edge of the mullle in such manner that the charge can be filled in at 1. This cycle of operations is thereupon repeated until the mullie is again filled with a piston and a charge. In the bend 9 there obviously remains behind both a part of the residues from the previous reduction and pistons, so-that the fresh charge is only in the mullie.

The mode of working is described abox e for the case in which the muffle is intended to be entirely emptied and filled in one cycle of operations. smelting can however be carried out continuously, in which case only a single piston and a correspondingly small quantity of residues are discharged. at the outlet for the residues, and at certain intervals of time depending on the rapidity of the reduction process a new piston and a new charge is pressed in. The zinc vapors can escape neither upwardly nor downwardly, as the second piston is never pressed down from above to a point below the top gas-ducts, but remains somewhat above the latter, while the charge in the bend 9 prevents the vapors escaping below.

The above described apparatus is preferahly employed for ores which indeed sinter, but do not slag so considerably that the gasduets become wholly filled up. The pistons therefore have only to bring about a uniform passage of the charge through the muffle. For ores which slag considerablyand gradually block up the gasducts, the individual pistons have a special form, represented in the retort illustrated in Figs. 4 to 8. In Figs. 1 to 8 the retort is shown as provided with two fume channels 112. that have open slots in the walls adjacent the charge, and the pistons are H-shaped to slide along the channels. The stems of the pistons have horizontal, transverse passages Z that register with the slots in the fume channels. Passages is partly in the pistons proper and partly in their removable stems connect with the passages 1 so that the fumes and gases below the piston rise through the passages 70 into those l and are thereby discharged into the open slotted side of channels m. The mode of working remains the same as that hereinbefore described, but each individual piston has gas-ducts through which the zinc vapors and reduction gases can, pass. In those faces of the piston which face downwardly holes ic are arranged connected to the duct Z which in turn opens into the slots m, to and outside of which are directly connected the receivers. The zinc vapors and reduction gases from the charge which is held by each individual piston escape through the holes is and the duct l into the slots m and then pass to the receivers. Since the slag tends to sink, the holes lo remain open; moreover, after each passage of the pistons throughthe muflle there is an opportunity of checking whether the holes are blocked up or not. The slots m are protected from the entry of the charge by the stems of the pistons.

I claim.

1. A zinc retort piston of refractory material substantially filling the retort, having a refractory stem. for supporting the piston thereabove to maintain adjacent pistons spaced and provide a chamber for the charge without compressing the same.

2. A zinc retort piston of refractory material having a refractory stem removable from, arranged to rest on and interfit with the piston.

3. A retort piston of refractory material having a refractory stem and ducts for fumes and gas for connecting the s ace on one side of a piston to that on the 0 her.

4. A retort piston of refractory material having a separate stem of refractory material intertitting with the piston, and ducts, partly in the piston and partly in the stem, and arranged to conduct fumes and gas from one side of the piston to the other.-

5. The method of working zinc retorts which comprises passing through an openended retort a plurality of separately supported quantities of the charge.

In testimony whereof I have atlixed my signature in presence of two witnesses.

ALEXANDER ROI'IZHEIM. [L-s.]

Witnesses I HELEN NUrnR, UREBULM SANNUCK. 

